This is not Casper The Friendly Ghost. Ghost peaks take up precious instrument time and keep us in the lab long after everyone else has gone home. Whether using a FID, PID, ECD, or MS; you will encounter ghost peaks. Those of us using a non-specific detector (i.e. FID) need not be lost when it comes to these elusive compounds. Shown in the figure are two EPA 8270 blank chromatograms (Internal Standards & Surrogates only) run back to back using a 5Sil MS column, 30m x 0.25mm x 0.25df. The interesting thing about this chromatogram are the three different types of ghost peaks shown: carryover (PAHs), O-ring bleed (triphenylphosphine oxide), and contamination (phthalates). The 2nd blank is relatively clean. Follow these tips: don’t overload your liner with sample, condition your injection port and column prior to analysis & do run a blank after high concentration standards or samples. Don’t be superstitious follow these rules and you will be on your way to a trouble free analysis.
